[MEXICO CITY] Researchers have shown that the abundance of
Mexican mangroves has a direct effect on the health of the fishing
industry and the local economy.

The study, published in the Proceedings of the National Academy of Sciences, analysed 13 regions in four states — Baja California Sur, Nayarit, Sinaloa and Sonora — in Mexico's Gulf of California.

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Tourist development and shrimp farms have affected the
mangrove forests in the region, destroying trees and wetlands to make
way for beaches.

Octavio Aburto-Oropeza, a researcher at the Center for Marine
Biodiversity and Conservation, at the US-based Scripps Institution of
Oceanography, and colleagues analysed over 9,000 fishing landing
records between 2001 and 2005 from the Mexican National Fisheries and
Aquaculture Commission (CONAPESCA).

Landings averaged 11,600 tonnes, and generated an average annual income of US$19 million for fishermen across the 13 regions.

They found that landings increased with the total area of
mangrove fringe, the section of mangrove that is the nursery and
feeding ground for a great variety of marine species of economic
importance.

"In the Gulf of California, 32 per cent of the varieties of
fish and crabs with commercial importance are related to the local
abundance of mangrove," Aburto-Oropeza told SciDev.Net.

Aburto-Oropeza and colleagues estimate the value of mangrove
ecosystem services to be an average of US$37,500 per hectare per year,
far higher than the Mexican government value of around US$1,000.

Mangroves across the regions are disappearing at an annual
rate of about two per cent. "The region of La Paz, in the peninsula of
Baja California, lost 23 per cent of the mangrove cover in two
decades," says Aburto-Oropeza.

"A considerable amount of hectares of mangrove have lost the
red mangrove plants that have contact with the sea, which are the main
habitat for species of commercial importance," says Aburto-Oropeza.

The researchers want to see mangrove conservation and more
efficient and sustainable use of wetlands. "To recover a mangrove
ecosystem takes hundreds of years. It is very expensive, but the costs
of its loss are several orders of magnitude greater," says
Aburto-Oropeza.